Rhea (bird)
genus of birds, ratites
The rhea ( REE-ə), also known as the ñandú ( nyan-DOO) is a South American ratite (flightless bird without a keel on the sternum bone) of the order Rheiformes. Rheas are distantly related to the two African ostriches and Australia's emu (the largest, second-largest and third-largest living ratites, respectively), with rheas placing just behind the emu in height and overall size.
Most taxonomic authorities recognize two extant species: the greater, or American, rhea (Rhea americana); and the lesser, or Darwin's, rhea (Rhea pennata). The International Union for Conservation of Nature (IUCN) classifies the puna rhea as another species instead of a subspecies of the lesser rhea. The IUCN currently rates the greater and puna rheas as near-threatened in their native ranges, while Darwin's rhea is of least concern, having recovered from past threats to its survival. In addition, the feral population of the greater rhea in Germany appears to be growing. However, control efforts are underway and seem to succeed in controlling the birds' population growth. Similarly to ostriches and emus, rheas are fairly popular livestock and pets, regularly kept and bred on farms, ranches, private parks, and by aviculturists, mainly in North and South America and Europe.
Etymology
The name "rhea" was used in 1752 by Paul Möhring and adopted as the English common name. Möhring named the bird after the Greek Titan Rhea, whose Ancient Greek name (Ῥέα) is thought to come from ἔρα (éra, "ground").
This brief starts where responsible research should: with the source description of “Rhea (bird)” as genus of birds, ratites. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the science & nature register because the source frames it as genus of birds, ratites. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Jul 5, 2026. The linked authority identifier is Q19171. The Library of Congress control number is sh92001446. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1752.
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This entry incorporates text from “Rhea (bird)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.